The present invention relates to a device for mounting and removing die blankets of a rotary cutting anvil cylinder. The rotary die-cutting operation of the cardboard or corrugated cardboard is well-known and utilizes inter alia, on the one hand, a tool holder cylinder generally consisting of a metal cylinder body on which shells are fixed, preferably made of wood, in which metal cutting rules are inserted and, on the other hand, a cutting anvil cylinder commonly called anvil. This anvil cylinder consists of a metal cylinder body on which blanket strips are mounted, generally made of a plastic such as polyurethane for example.
The tool holder cylinder can be covered by various shells having cutting rule configurations according to the shapes and dimensions of the boxes to be cut. The matter to be cut, in this case corrugated cardboard, passes between the tool holder cylinder and the cutting anvil cylinder and, at the time of the die-cutting operation, the metal rules of the tool holder cylinder penetrate more or less deeply into the blanket strips, which causes after a certain number of hours of cutting a wear of some of these blanket strips.
The blanket strips are generally mounted side by side over the width of the cylinder body of the anvil cylinder. The cylinder body has a groove extending over its entire width. In order to fix the blanket strips, the ends of them are inserted in the groove arranged in the anvil cylinder by means of a mallet. Each end of the blanket strips can be reinforced by a metal reinforcement, one end having a centering nose and the other a notch into which fits the centering nose. Due to this fixing, the mounting thus carried out is practically permanent and requires a removal by force.
The wear of the surface of the blanket strips is not regular over the entire width of the anvil cylinder and, obviously, if the wear interferes with the diecutting or creasing operation of the cardboard, an acceptable surface quality of the die blanket of the anvil cylinder should be restored.
Generally, to restore the surface quality, the external diameter of the die blanket of the anvil cylinder is rectified by grinding or any other similar machining. Due to the high production rate of the rotary die-cutting machines, this operation must be frequently repeated and, in addition to causing an important reduction in the productivity of the machine, it involves a significant consumption of blanket strips.